Fork offset

[HarryJune]

Currently I have RockShox boxxer 180 forks on my cannondale Moterra se, these are dual crown with a 55mm offset.
I am considering purchasing single crown forks, maybe Zeb , from my little research these come in a 44mm offset.
what will the different offset mean to the bike?
Am I better of looking for forks with the same offset or is - 10mm not worth worrying about?
Thanks

 

[flash]

Technically, a shorter offset is more stable at higher speeds and a longer offset is more stable at lower speeds. I did this change twice on my Merida's. Yes, there was a difference but it was slight. Took no more than a couple of rides and I forgot all about it.

Gordon

 

[Mikerb]

I dont think you can treat offset in isolation of other geometry factors most specifically wheel size and head angle, and what sort of performance you are looking for with that specific bike. Check out Singletracks for a more detailed article on offset and what effect it has on trail and therefore on handling. Armed with that information for your specific bike you may be best advised to get advice from Cannondale or at least a dealer.......................if you buy forks with a shorter offset and dont like the results, it will be an expensive mistake!

 

[HarryJune]

Thanks, I think I’ll need to do more research.

 

[RustyMTB]

This is decent on the intricacies of offset. Must admit it's not something I've spent much time thinking about.

Fork offset: what is it and how does it affect your riding? - MBR

There's lots of talk and chin-stroking about fork offset amongst the MTB illuminati at the mo. What is it? Should you know what your current forkset is?

www.mbr.co.uk

 

[HarryJune]

Good article, thanks, now I need advice on what forks to purchase, Lyrik rockshox maybe as smaller and lighter than the Zeb. My riding is mainly Swinley and Surrey hills not hardcore downhill.

 

[Gary]

You were riding a BOXXER at swinley? ?

??

 

[HarryJune]

You were riding a BOXXER at swinley? ?

??

Yes and still am, that’s why I’m looking for a change of fork, slight overkill?

 

[R120]

Of more relevance is that if you are looking at swapping the 180mm boxer that comes as standard on the bike, to a 180mm dingle crown such as a Zeb, the single crown is actually likely to have a longer axle to crown than the dual crown.

@Gary will know better than me, but I would have thought putting a 180mm signal crown on would actually raise the front end, and IIRC the regular Monterra's run 51 mm offset 160mm forks, e.g

* PDP

www.cannondale.com

"RockShox Zeb Ultimate, Charger 2.1 RC2, 160mm, DebonAir, 15x110, 51mm offset"

Having said that I think the SE is the only one in the line up on 27.5?

Point being you might feck the handling, and if going to single crown actually be better off looking at a shorter travel fork.

 

[HarryJune]

Yes I’m going for 160mm Lyrik ultimate 51mm offset.( if I can find them at a fair price)
As you pointed out the other moterra’s run 160mm.
The SE is 29” wheel as the other moterra’s are.
Thanks for your input.

 

[Gary]

Dual crown forks are adjustable in axle to crown length to some extent by raising or lowering the stanchions in the crowns (even more so if you run a dropped upper crown. The lower crown on a Boxxer is slimmer than any single crown and also straight. So like for like travel a Boxxer can be shorter axle to crown height than a single crown fork by over 20mm. This will be Especially true of the Zeb.

 

[Gary]

Don't sweat a 4mm difference in offset.

i run forks with massively different offsets on various wheelsizes (on different bikes) and instantly figure out the difference when switching from bike to bike. You may notice a slight chance first ride but after that it is what it is.
Half the chat from 99.9% of mtbers about offset is basically bullshit and they wouldn't even talk about it if a few companies had brought it up as a selling point a few years back

 

[R120]

Yes I’m going for 160mm Lyrik ultimate 51mm offset.( if I can find them at a fair price)
As you pointed out the other moterra’s run 160mm.
The SE is 29” wheel as the other moterra’s are.
Thanks for your input.

I would check out the ZEB too, I went from a Lyric ultimate to a ZEB Ultimate and whilst the difference isn’t night and day, with the extra weight of an EMTB and if you are running 220mm rotors the performance difference is worth it IMO, especially if you are coming off a dual crown.

 

[Gary]

One more thing to consider when changing from a dual crown fork to a shorter (or even the same travel) single crown is stem height. You'll need to figure this out yourself by adding and removing spacers so don't make the mistake of cutting the steerer too short until you're settled on bar/stem height

 

[HarryJune]

Don't sweat a 4mm difference in offset.

i run forks with massively different offsets on various wheelsizes (on different bikes) and instantly figure out the difference when switching from bike to bike. You may notice a slight chance first ride but after that it is what it is.
Half the chat from 99.9% of mtbers about offset is basically bullshit and they wouldn't even talk about it if a few companies had brought it up as a selling point a few years back

The Zeb fork I was considering was -10mm, where as the lyric at 4mm is no concern.
Lyric ultimate 160mm 51mm a good choice option?

 

[Gary]

I would check out the ZEB too, I went from a Lyric ultimate to a ZEB Ultimate and whilst the difference isn’t night and day, with the extra weight of an EMTB and if you are running 220mm rotors the performance difference is worth it IMO, especially if you are coming off a dual crown.

The flipside of that is of course that the (slightly) lighter Lyrik may transform (or partly contribute to a lighter/more playful/agile feel to the bike for tamer riding (Surrey, I'm looking at you)

 

[HarryJune]

Cross posts.

 

[Gary]

The Zeb fork I was considering was -10mm, where as the lyric at 4mm is no concern.

Neither is a concern.
you're worrying about something you don't even understand

 

[Gary]

Cross posts.

It's cool. We Scots can read English too (Only a little better )

 

[R120]

The Lyric is a great fork, and on a regular MTB I would go for it all day long. I ride Surrey hills, but have found the ZEB holds a line better with the weight of an EMTB behind it, and feels a lot more direct.

Having said that my ZEB is 180mm as was my Lyric and in my opinion the difference between a ZEB and a Lyric is far more noticeable at 180mm than it is at 160mm.

 

[HarryJune]

Neither is a concern.
you're worrying about something you don't even understand

Correct, I was just going like for like on offset. That’s why I asked.

 

[Gary]

Correct, I was just going like for like on offset.

Yeah, Based on nothing.

Remember, the moterra won't have even been designed with (just) a 55mm offset Boxxer in mind.

Even if you go down to a 42mm Lyrik you won't ruin the handling. it'll just alter the steering traits and stability a touch.

 

[HarryJune]

The Lyric is a great fork, and on a regular MTB I would go for it all day long. I ride Surrey hills, but have found the ZEB holds a line better with the weight of an EMTB behind it, and feels a lot more direct.

Having said that my ZEB is 180mm as was my Lyric and in my opinion the difference between a ZEB and a Lyric is far more noticeable at 180mm than it is at 160mm.

I was thinking the ZEB would be a little overkill as the boxxer are considering 70% of my rides are at Swinley as it’s only a 5 minute cycle ride from me.

 

[Gary]

The Lyric is a great fork, and on a regular MTB I would go for it all day long. I ride Surrey hills, but have found the ZEB holds a line better with the weight of an EMTB behind it, and feels a lot more direct.

I totally agree with you on it's directness and stiffness and I've also ridden quite a few Lyriks and Zebs.
Rider size/weight/Strength/ability and even riding style makes a pretty big difference too though in regards to personal preference.
and not everyone even wants the most latterally stiff fork.
There's not a single Zeb forked 2021 Eeb I've preferred to my ol Esommet with it's tired ol Lyrik and this is partly down the the entire bikes increased weight but also their increased stiffness plays a part too.

 

[R120]

Yup Lyric would be totally fine - I actually think it’s a better fork than the ZEB in terms of outright performance, best for k I have had for sure, but at 180mm as I run it the added stifnesss is noticeable particular unde hard braking (ember I run a 223 front rotor)

 

[Gary]

Yeah. again I can't disagree. To be run at 160mm I'd def go for a Lyrik over a Zeb whatever the bike (Eeb or normal)
But that's me

 

[HarryJune]

Thanks for your help guys, lyrik it is then.
Now where to find them at a good price.

 

[Gary]

It's funny. Earlier today I serviced and replaced the (original) corroded cables on a '96 GT ZAskar. OG ball burnished frame in 16" with a threaded 80mm Manitou fork and full '95 9 speed XT incl V-brakes. I couldn't help but reminisce to back when mountain bikes were actually light and simple and no one worried about stanchion diameter, dropout offsets, reach, chainstay length and all the other bollocks folk are always fretting over these days.
Think I'll take it out in the morning for a few sweet wheelies before he collects it.

 

[Gary]

Now where to find them at a good price.

You'll be lucky